There are actually two papers being cited. The other one is titled Single-particle cryo-EM at atomic resolution: https://www.nature.com/articles/s41586-020-2829

There are actually two papers being cited. The other one is titled Single-particle cryo-EM at atomic resolution: https://www.nature.com/articles/s41586-020-2829-0 https://www.nature.com/articles/s41586-020-2829-0